Telecommunications and data networks rely on the use of both long and short optical fiber cables. The long optical fiber cables are typically several hundred meters to many kilometers and are used to interconnect distant locations, such as data centers located in different cities or different countries. The short optical fiber cables are typically 0.5 meters up to tens of meters and are referred to in the art as “jumpers” or “patch cords” that have connectors on each end. These shorter optical fiber cables are used in offices, data centers and like facilities to optically connect data storage or optical communication equipment within a room, a building or even between buildings. For example, a given patch cord may be attached to a first port in a first equipment rack, run through the floor or other conduit, and terminate at a second port in a second equipment rack a few meters away. FIG. 1 shows how multiple patch cords PC can be connected at one end to respective ports P of an equipment rack ER. Presently, tens, hundreds or even thousands of such patch cords can be used in offices, data centers and like facilities.
As part of routine operation or maintenance, a technician may be required to trace the path of a patch cord from one end to the other within a given facility, e.g., for servicing, replacement, relocation or testing. This operation can be done manually by physically accessing the patch cord and following it from one end to the other over its route. Unfortunately, this is time intensive and labor intensive and is potentially disruptive to the network.
More recently, traceable patch cords have been developed that allow for a technician to quickly identify the terminal ends of a given patch cord. Traceable patch cords rely on tracer optical fibers integrated into the patch cord. The first end of the tracer optical fiber resides at a first connector of the traceable patch cord. Light from the light source is coupled into the first end of the tracer optical fiber and is emitted from the second end, which is located at the second connector of the traceable patch cord. The technician can then observe the light emitted from second end of the tracer optical fiber at the second connector to locate the second connector of the traceable patch cord among a collection of patch cords such as shown in FIG. 1.
The optical power of the visible light launched into the first end of the tracer optical fiber may be relatively high. Depending on the exact power level used, the emission from the light source may approach desired eye safety requirements. This in turn may require using a lower optical power to meet desired eye safely requirements. Unfortunately, this may also reduce the efficacy of the traceable patch cord because it may reduce the “brightness” (more accurately, the luminance) of the light emitted from the tracing fiber, making it harder for a technician to find the end of the traceable patch cord.